In the field of diagnostic testing of biological fluids for the presence of drugs, viral disease, bacterial infections, and the like, samples are collected, reacted with reagents, and the results of the reactions analyzed using well known techniques. The reagents used in such tests are typically purchased in and drawn from vials or other containers which are often arranged for convenience in preformed packs having a plurality of such vials containing the reagents required for specific tests. For economy and practicality, each vial typically contains an aliquot of reagent sufficient to test a number of samples. A problem with such "multi dose" reagent packs is that once open, the reagents may become contaminated or concentrated through evaporation. For example, the properties of certain reagents may be effected by exposure to light or air, the passage of time, or exposure to other reagents or contaminents.
The vials of such packs could be individually reclosed using individual screw on or other closures typically provided with such vials. However, such individual closures can be misplaced or lost when separated from their respective vials. In addition, it is time consuming and inconvenient to individually open and reclose each vial with a separate closure, particularly in an automatic testing environment where test set up time and the time between tests can have a critical impact on through put.
Modern testing means require specific test protocal with specific reagents which are selected to identify for example, a particular analyte or analytes. The protocal specifies the sequence in which sample and reagents are to be introduced, the timing for the introduction of sample and reagents, the volumes of each to be used, and other conditions to be controlled such as temperature. The resulting mixture is typically allowed to incubate for a predetermined time and is then read, optically or otherwise, to determine the presence and concentration of the specific analyte which the assay is designed to identify.
Automated clinical analyzers are capable of performing imuno assays on an entire batch of samples simultaneously. In some types of known analyzers such as the well known TDx.RTM. clinical analyzer manufactured by Abbott Laboratories of North Chicago, Ill., a batch of sample containers are mounted radially about a rotatable cassette together with a corresponding number of reagent containers. The carousel is then mounted inside the analyzer. Inside the analyzer, the carousel rotates stepwise to move each corresponding sample container and reaction container paired first to a position adjacent a preparation station, and then to a second position adjacent a reading station. A mechanical apparatus having pipeting means and typically operating under program control is located in proximity to the preparation station. Also located in proximity to the preparation station are a plurality of reagent containers which contain the reagents required to perform a specific assay on the batch of samples contained in the sample containers. The reagent containers may be individual containers or may be configurated as an integrated pack.
At the preparation station, the mechanical apparatus and pipeting means operate to access and transfer volumes of sample from a sample container and reagents from the reagent containers into a reaction container according to the protocal established for the specific assay. When the mechanical apparatus completes the preparation of the reaction mixture according to the test protocal, the carousel rotates positioning the next corresponding sample container and reaction container pair adjacent the preparation station, and moving the previous pair toward the reading station. Known carousels typically hold twenty to twenty-five sample containers.
Through put limitations associated with the need and desire to test the same biological sample for more than one analyte such as when testing for the usage of a number of selected illegal drugs presents problems in that each test must be carried out sequentially. In the past, between tests, such analyzers were set up with new reagents and new samples being loaded and instructions for the new test located or entered. The requirement of changing reagent packs for each assay has an adverse impact on through put of the analyzer. Where multiple assays are to be performed on the same batch of samples or on different samples, the requirement of changing reagent containers for each assay has an even more severe and diversed impact on the though put of the system. Decreased through put increases both the time and cost associated with such assays.
Several approaches to solving the problems of through put of these analyzers have been provided, for example in providing unit dose for utilized reagent containers each containing an aliquot of reagents sufficient to carry out a specific assay on one sample. These containers are mounted on the analyzer carousel in positions corresponding to each sample container. With utilized reagent containers, different imuno assays can be carried out on each sample. For example, one sample can be assayed for a certain class of drugs, the next for the presence of a strain of virus, the next for a certain class bacteria, and so forth.
The unit dose approach has not provided a complete solution to the through put problems. However, multidose reagent pack and carousel for automated clinical analyzer have been adapted to hold such packs together with a plurality of conventional sample containers which contain samples to be assayed by the analyzer. For example, a reagent pack which includes a vial carrier having a plurality of vial receiving wells for containing a corresponding plurality of mutlidose reagent containing vials has been presented for automated clinical analyzer use. In addition, containment apparatus which is capable of holding a plurality of samples, the sample containers being adapted to be expeditiously mounted sequentially on carousels of a selected plurality of optimized clinical analyzers, the analyzers being networked to perform a selected battery of tests on each of the plurality of the samples has been proposed. All of these approaches are geared for increasing though put and performing multiple tests on samples using multiples of reagents, thus increasing the need for open reagent vials capable of delivering multiple doses of reagents at or near design concentrations as well as the avoidance of evaporation due to the requirement of continuously being open to air and pipeting.
The present invention has as a primary objective to satisfy the foregoing needs by providing a sample and reagent containment mechanism especially adapted for use in an automated analyzer network of the type described and having the foregoing and other features and advantages. Additional objectives are achieved by the evaporation chimney when utilized in any open mouth liquid containers wherein valuable liquids are maintained and which require immediate i.e., open access. In all of these situations the exposed liquids require maintenance of concentration and reduced evaporation into air or other environmental gases.